| /* |
| * Driver for Atmel AT32 and AT91 SPI Controllers |
| * |
| * Copyright (C) 2006 Atmel Corporation |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/clk.h> |
| #include <linux/module.h> |
| #include <linux/platform_device.h> |
| #include <linux/delay.h> |
| #include <linux/dma-mapping.h> |
| #include <linux/dmaengine.h> |
| #include <linux/err.h> |
| #include <linux/interrupt.h> |
| #include <linux/spi/spi.h> |
| #include <linux/slab.h> |
| #include <linux/platform_data/dma-atmel.h> |
| #include <linux/of.h> |
| |
| #include <linux/io.h> |
| #include <linux/gpio/consumer.h> |
| #include <linux/pinctrl/consumer.h> |
| #include <linux/pm_runtime.h> |
| |
| /* SPI register offsets */ |
| #define SPI_CR 0x0000 |
| #define SPI_MR 0x0004 |
| #define SPI_RDR 0x0008 |
| #define SPI_TDR 0x000c |
| #define SPI_SR 0x0010 |
| #define SPI_IER 0x0014 |
| #define SPI_IDR 0x0018 |
| #define SPI_IMR 0x001c |
| #define SPI_CSR0 0x0030 |
| #define SPI_CSR1 0x0034 |
| #define SPI_CSR2 0x0038 |
| #define SPI_CSR3 0x003c |
| #define SPI_FMR 0x0040 |
| #define SPI_FLR 0x0044 |
| #define SPI_VERSION 0x00fc |
| #define SPI_RPR 0x0100 |
| #define SPI_RCR 0x0104 |
| #define SPI_TPR 0x0108 |
| #define SPI_TCR 0x010c |
| #define SPI_RNPR 0x0110 |
| #define SPI_RNCR 0x0114 |
| #define SPI_TNPR 0x0118 |
| #define SPI_TNCR 0x011c |
| #define SPI_PTCR 0x0120 |
| #define SPI_PTSR 0x0124 |
| |
| /* Bitfields in CR */ |
| #define SPI_SPIEN_OFFSET 0 |
| #define SPI_SPIEN_SIZE 1 |
| #define SPI_SPIDIS_OFFSET 1 |
| #define SPI_SPIDIS_SIZE 1 |
| #define SPI_SWRST_OFFSET 7 |
| #define SPI_SWRST_SIZE 1 |
| #define SPI_LASTXFER_OFFSET 24 |
| #define SPI_LASTXFER_SIZE 1 |
| #define SPI_TXFCLR_OFFSET 16 |
| #define SPI_TXFCLR_SIZE 1 |
| #define SPI_RXFCLR_OFFSET 17 |
| #define SPI_RXFCLR_SIZE 1 |
| #define SPI_FIFOEN_OFFSET 30 |
| #define SPI_FIFOEN_SIZE 1 |
| #define SPI_FIFODIS_OFFSET 31 |
| #define SPI_FIFODIS_SIZE 1 |
| |
| /* Bitfields in MR */ |
| #define SPI_MSTR_OFFSET 0 |
| #define SPI_MSTR_SIZE 1 |
| #define SPI_PS_OFFSET 1 |
| #define SPI_PS_SIZE 1 |
| #define SPI_PCSDEC_OFFSET 2 |
| #define SPI_PCSDEC_SIZE 1 |
| #define SPI_FDIV_OFFSET 3 |
| #define SPI_FDIV_SIZE 1 |
| #define SPI_MODFDIS_OFFSET 4 |
| #define SPI_MODFDIS_SIZE 1 |
| #define SPI_WDRBT_OFFSET 5 |
| #define SPI_WDRBT_SIZE 1 |
| #define SPI_LLB_OFFSET 7 |
| #define SPI_LLB_SIZE 1 |
| #define SPI_PCS_OFFSET 16 |
| #define SPI_PCS_SIZE 4 |
| #define SPI_DLYBCS_OFFSET 24 |
| #define SPI_DLYBCS_SIZE 8 |
| |
| /* Bitfields in RDR */ |
| #define SPI_RD_OFFSET 0 |
| #define SPI_RD_SIZE 16 |
| |
| /* Bitfields in TDR */ |
| #define SPI_TD_OFFSET 0 |
| #define SPI_TD_SIZE 16 |
| |
| /* Bitfields in SR */ |
| #define SPI_RDRF_OFFSET 0 |
| #define SPI_RDRF_SIZE 1 |
| #define SPI_TDRE_OFFSET 1 |
| #define SPI_TDRE_SIZE 1 |
| #define SPI_MODF_OFFSET 2 |
| #define SPI_MODF_SIZE 1 |
| #define SPI_OVRES_OFFSET 3 |
| #define SPI_OVRES_SIZE 1 |
| #define SPI_ENDRX_OFFSET 4 |
| #define SPI_ENDRX_SIZE 1 |
| #define SPI_ENDTX_OFFSET 5 |
| #define SPI_ENDTX_SIZE 1 |
| #define SPI_RXBUFF_OFFSET 6 |
| #define SPI_RXBUFF_SIZE 1 |
| #define SPI_TXBUFE_OFFSET 7 |
| #define SPI_TXBUFE_SIZE 1 |
| #define SPI_NSSR_OFFSET 8 |
| #define SPI_NSSR_SIZE 1 |
| #define SPI_TXEMPTY_OFFSET 9 |
| #define SPI_TXEMPTY_SIZE 1 |
| #define SPI_SPIENS_OFFSET 16 |
| #define SPI_SPIENS_SIZE 1 |
| #define SPI_TXFEF_OFFSET 24 |
| #define SPI_TXFEF_SIZE 1 |
| #define SPI_TXFFF_OFFSET 25 |
| #define SPI_TXFFF_SIZE 1 |
| #define SPI_TXFTHF_OFFSET 26 |
| #define SPI_TXFTHF_SIZE 1 |
| #define SPI_RXFEF_OFFSET 27 |
| #define SPI_RXFEF_SIZE 1 |
| #define SPI_RXFFF_OFFSET 28 |
| #define SPI_RXFFF_SIZE 1 |
| #define SPI_RXFTHF_OFFSET 29 |
| #define SPI_RXFTHF_SIZE 1 |
| #define SPI_TXFPTEF_OFFSET 30 |
| #define SPI_TXFPTEF_SIZE 1 |
| #define SPI_RXFPTEF_OFFSET 31 |
| #define SPI_RXFPTEF_SIZE 1 |
| |
| /* Bitfields in CSR0 */ |
| #define SPI_CPOL_OFFSET 0 |
| #define SPI_CPOL_SIZE 1 |
| #define SPI_NCPHA_OFFSET 1 |
| #define SPI_NCPHA_SIZE 1 |
| #define SPI_CSAAT_OFFSET 3 |
| #define SPI_CSAAT_SIZE 1 |
| #define SPI_BITS_OFFSET 4 |
| #define SPI_BITS_SIZE 4 |
| #define SPI_SCBR_OFFSET 8 |
| #define SPI_SCBR_SIZE 8 |
| #define SPI_DLYBS_OFFSET 16 |
| #define SPI_DLYBS_SIZE 8 |
| #define SPI_DLYBCT_OFFSET 24 |
| #define SPI_DLYBCT_SIZE 8 |
| |
| /* Bitfields in RCR */ |
| #define SPI_RXCTR_OFFSET 0 |
| #define SPI_RXCTR_SIZE 16 |
| |
| /* Bitfields in TCR */ |
| #define SPI_TXCTR_OFFSET 0 |
| #define SPI_TXCTR_SIZE 16 |
| |
| /* Bitfields in RNCR */ |
| #define SPI_RXNCR_OFFSET 0 |
| #define SPI_RXNCR_SIZE 16 |
| |
| /* Bitfields in TNCR */ |
| #define SPI_TXNCR_OFFSET 0 |
| #define SPI_TXNCR_SIZE 16 |
| |
| /* Bitfields in PTCR */ |
| #define SPI_RXTEN_OFFSET 0 |
| #define SPI_RXTEN_SIZE 1 |
| #define SPI_RXTDIS_OFFSET 1 |
| #define SPI_RXTDIS_SIZE 1 |
| #define SPI_TXTEN_OFFSET 8 |
| #define SPI_TXTEN_SIZE 1 |
| #define SPI_TXTDIS_OFFSET 9 |
| #define SPI_TXTDIS_SIZE 1 |
| |
| /* Bitfields in FMR */ |
| #define SPI_TXRDYM_OFFSET 0 |
| #define SPI_TXRDYM_SIZE 2 |
| #define SPI_RXRDYM_OFFSET 4 |
| #define SPI_RXRDYM_SIZE 2 |
| #define SPI_TXFTHRES_OFFSET 16 |
| #define SPI_TXFTHRES_SIZE 6 |
| #define SPI_RXFTHRES_OFFSET 24 |
| #define SPI_RXFTHRES_SIZE 6 |
| |
| /* Bitfields in FLR */ |
| #define SPI_TXFL_OFFSET 0 |
| #define SPI_TXFL_SIZE 6 |
| #define SPI_RXFL_OFFSET 16 |
| #define SPI_RXFL_SIZE 6 |
| |
| /* Constants for BITS */ |
| #define SPI_BITS_8_BPT 0 |
| #define SPI_BITS_9_BPT 1 |
| #define SPI_BITS_10_BPT 2 |
| #define SPI_BITS_11_BPT 3 |
| #define SPI_BITS_12_BPT 4 |
| #define SPI_BITS_13_BPT 5 |
| #define SPI_BITS_14_BPT 6 |
| #define SPI_BITS_15_BPT 7 |
| #define SPI_BITS_16_BPT 8 |
| #define SPI_ONE_DATA 0 |
| #define SPI_TWO_DATA 1 |
| #define SPI_FOUR_DATA 2 |
| |
| /* Bit manipulation macros */ |
| #define SPI_BIT(name) \ |
| (1 << SPI_##name##_OFFSET) |
| #define SPI_BF(name, value) \ |
| (((value) & ((1 << SPI_##name##_SIZE) - 1)) << SPI_##name##_OFFSET) |
| #define SPI_BFEXT(name, value) \ |
| (((value) >> SPI_##name##_OFFSET) & ((1 << SPI_##name##_SIZE) - 1)) |
| #define SPI_BFINS(name, value, old) \ |
| (((old) & ~(((1 << SPI_##name##_SIZE) - 1) << SPI_##name##_OFFSET)) \ |
| | SPI_BF(name, value)) |
| |
| /* Register access macros */ |
| #ifdef CONFIG_AVR32 |
| #define spi_readl(port, reg) \ |
| __raw_readl((port)->regs + SPI_##reg) |
| #define spi_writel(port, reg, value) \ |
| __raw_writel((value), (port)->regs + SPI_##reg) |
| |
| #define spi_readw(port, reg) \ |
| __raw_readw((port)->regs + SPI_##reg) |
| #define spi_writew(port, reg, value) \ |
| __raw_writew((value), (port)->regs + SPI_##reg) |
| |
| #define spi_readb(port, reg) \ |
| __raw_readb((port)->regs + SPI_##reg) |
| #define spi_writeb(port, reg, value) \ |
| __raw_writeb((value), (port)->regs + SPI_##reg) |
| #else |
| #define spi_readl(port, reg) \ |
| readl_relaxed((port)->regs + SPI_##reg) |
| #define spi_writel(port, reg, value) \ |
| writel_relaxed((value), (port)->regs + SPI_##reg) |
| |
| #define spi_readw(port, reg) \ |
| readw_relaxed((port)->regs + SPI_##reg) |
| #define spi_writew(port, reg, value) \ |
| writew_relaxed((value), (port)->regs + SPI_##reg) |
| |
| #define spi_readb(port, reg) \ |
| readb_relaxed((port)->regs + SPI_##reg) |
| #define spi_writeb(port, reg, value) \ |
| writeb_relaxed((value), (port)->regs + SPI_##reg) |
| #endif |
| /* use PIO for small transfers, avoiding DMA setup/teardown overhead and |
| * cache operations; better heuristics consider wordsize and bitrate. |
| */ |
| #define DMA_MIN_BYTES 16 |
| |
| #define SPI_DMA_TIMEOUT (msecs_to_jiffies(1000)) |
| |
| #define AUTOSUSPEND_TIMEOUT 2000 |
| |
| struct atmel_spi_caps { |
| bool is_spi2; |
| bool has_wdrbt; |
| bool has_dma_support; |
| bool has_pdc_support; |
| }; |
| |
| /* |
| * The core SPI transfer engine just talks to a register bank to set up |
| * DMA transfers; transfer queue progress is driven by IRQs. The clock |
| * framework provides the base clock, subdivided for each spi_device. |
| */ |
| struct atmel_spi { |
| spinlock_t lock; |
| unsigned long flags; |
| |
| phys_addr_t phybase; |
| void __iomem *regs; |
| int irq; |
| struct clk *clk; |
| struct platform_device *pdev; |
| unsigned long spi_clk; |
| |
| struct spi_transfer *current_transfer; |
| int current_remaining_bytes; |
| int done_status; |
| dma_addr_t dma_addr_rx_bbuf; |
| dma_addr_t dma_addr_tx_bbuf; |
| void *addr_rx_bbuf; |
| void *addr_tx_bbuf; |
| |
| struct completion xfer_completion; |
| |
| struct atmel_spi_caps caps; |
| |
| bool use_dma; |
| bool use_pdc; |
| bool use_cs_gpios; |
| |
| bool keep_cs; |
| bool cs_active; |
| |
| u32 fifo_size; |
| }; |
| |
| /* Controller-specific per-slave state */ |
| struct atmel_spi_device { |
| struct gpio_desc *npcs_pin; |
| u32 csr; |
| }; |
| |
| #define SPI_MAX_DMA_XFER 65535 /* true for both PDC and DMA */ |
| #define INVALID_DMA_ADDRESS 0xffffffff |
| |
| /* |
| * Version 2 of the SPI controller has |
| * - CR.LASTXFER |
| * - SPI_MR.DIV32 may become FDIV or must-be-zero (here: always zero) |
| * - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs) |
| * - SPI_CSRx.CSAAT |
| * - SPI_CSRx.SBCR allows faster clocking |
| */ |
| static bool atmel_spi_is_v2(struct atmel_spi *as) |
| { |
| return as->caps.is_spi2; |
| } |
| |
| /* |
| * Earlier SPI controllers (e.g. on at91rm9200) have a design bug whereby |
| * they assume that spi slave device state will not change on deselect, so |
| * that automagic deselection is OK. ("NPCSx rises if no data is to be |
| * transmitted") Not so! Workaround uses nCSx pins as GPIOs; or newer |
| * controllers have CSAAT and friends. |
| * |
| * Since the CSAAT functionality is a bit weird on newer controllers as |
| * well, we use GPIO to control nCSx pins on all controllers, updating |
| * MR.PCS to avoid confusing the controller. Using GPIOs also lets us |
| * support active-high chipselects despite the controller's belief that |
| * only active-low devices/systems exists. |
| * |
| * However, at91rm9200 has a second erratum whereby nCS0 doesn't work |
| * right when driven with GPIO. ("Mode Fault does not allow more than one |
| * Master on Chip Select 0.") No workaround exists for that ... so for |
| * nCS0 on that chip, we (a) don't use the GPIO, (b) can't support CS_HIGH, |
| * and (c) will trigger that first erratum in some cases. |
| */ |
| |
| static void cs_activate(struct atmel_spi *as, struct spi_device *spi) |
| { |
| struct atmel_spi_device *asd = spi->controller_state; |
| u32 mr; |
| |
| if (atmel_spi_is_v2(as)) { |
| spi_writel(as, CSR0 + 4 * spi->chip_select, asd->csr); |
| /* For the low SPI version, there is a issue that PDC transfer |
| * on CS1,2,3 needs SPI_CSR0.BITS config as SPI_CSR1,2,3.BITS |
| */ |
| spi_writel(as, CSR0, asd->csr); |
| if (as->caps.has_wdrbt) { |
| spi_writel(as, MR, |
| SPI_BF(PCS, ~(0x01 << spi->chip_select)) |
| | SPI_BIT(WDRBT) |
| | SPI_BIT(MODFDIS) |
| | SPI_BIT(MSTR)); |
| } else { |
| spi_writel(as, MR, |
| SPI_BF(PCS, ~(0x01 << spi->chip_select)) |
| | SPI_BIT(MODFDIS) |
| | SPI_BIT(MSTR)); |
| } |
| |
| mr = spi_readl(as, MR); |
| if (as->use_cs_gpios) |
| gpiod_set_value(asd->npcs_pin, 1); |
| } else { |
| u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0; |
| int i; |
| u32 csr; |
| |
| /* Make sure clock polarity is correct */ |
| for (i = 0; i < spi->master->num_chipselect; i++) { |
| csr = spi_readl(as, CSR0 + 4 * i); |
| if ((csr ^ cpol) & SPI_BIT(CPOL)) |
| spi_writel(as, CSR0 + 4 * i, |
| csr ^ SPI_BIT(CPOL)); |
| } |
| |
| mr = spi_readl(as, MR); |
| mr = SPI_BFINS(PCS, ~(1 << spi->chip_select), mr); |
| if (as->use_cs_gpios && spi->chip_select != 0) |
| gpiod_set_value(asd->npcs_pin, 1); |
| spi_writel(as, MR, mr); |
| } |
| |
| dev_dbg(&spi->dev, "activate NPCS, mr %08x\n", mr); |
| } |
| |
| static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi) |
| { |
| struct atmel_spi_device *asd = spi->controller_state; |
| u32 mr; |
| |
| /* only deactivate *this* device; sometimes transfers to |
| * another device may be active when this routine is called. |
| */ |
| mr = spi_readl(as, MR); |
| if (~SPI_BFEXT(PCS, mr) & (1 << spi->chip_select)) { |
| mr = SPI_BFINS(PCS, 0xf, mr); |
| spi_writel(as, MR, mr); |
| } |
| |
| dev_dbg(&spi->dev, "DEactivate NPCS, mr %08x\n", mr); |
| |
| if (!as->use_cs_gpios) |
| spi_writel(as, CR, SPI_BIT(LASTXFER)); |
| else if (atmel_spi_is_v2(as) || spi->chip_select != 0) |
| gpiod_set_value(asd->npcs_pin, 0); |
| } |
| |
| static void atmel_spi_lock(struct atmel_spi *as) __acquires(&as->lock) |
| { |
| spin_lock_irqsave(&as->lock, as->flags); |
| } |
| |
| static void atmel_spi_unlock(struct atmel_spi *as) __releases(&as->lock) |
| { |
| spin_unlock_irqrestore(&as->lock, as->flags); |
| } |
| |
| static inline bool atmel_spi_is_vmalloc_xfer(struct spi_transfer *xfer) |
| { |
| return is_vmalloc_addr(xfer->tx_buf) || is_vmalloc_addr(xfer->rx_buf); |
| } |
| |
| static inline bool atmel_spi_use_dma(struct atmel_spi *as, |
| struct spi_transfer *xfer) |
| { |
| return as->use_dma && xfer->len >= DMA_MIN_BYTES; |
| } |
| |
| static bool atmel_spi_can_dma(struct spi_master *master, |
| struct spi_device *spi, |
| struct spi_transfer *xfer) |
| { |
| struct atmel_spi *as = spi_master_get_devdata(master); |
| |
| if (IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) |
| return atmel_spi_use_dma(as, xfer) && |
| !atmel_spi_is_vmalloc_xfer(xfer); |
| else |
| return atmel_spi_use_dma(as, xfer); |
| |
| } |
| |
| static int atmel_spi_dma_slave_config(struct atmel_spi *as, |
| struct dma_slave_config *slave_config, |
| u8 bits_per_word) |
| { |
| struct spi_master *master = platform_get_drvdata(as->pdev); |
| int err = 0; |
| |
| if (bits_per_word > 8) { |
| slave_config->dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; |
| slave_config->src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; |
| } else { |
| slave_config->dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; |
| slave_config->src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; |
| } |
| |
| slave_config->dst_addr = (dma_addr_t)as->phybase + SPI_TDR; |
| slave_config->src_addr = (dma_addr_t)as->phybase + SPI_RDR; |
| slave_config->src_maxburst = 1; |
| slave_config->dst_maxburst = 1; |
| slave_config->device_fc = false; |
| |
| /* |
| * This driver uses fixed peripheral select mode (PS bit set to '0' in |
| * the Mode Register). |
| * So according to the datasheet, when FIFOs are available (and |
| * enabled), the Transmit FIFO operates in Multiple Data Mode. |
| * In this mode, up to 2 data, not 4, can be written into the Transmit |
| * Data Register in a single access. |
| * However, the first data has to be written into the lowest 16 bits and |
| * the second data into the highest 16 bits of the Transmit |
| * Data Register. For 8bit data (the most frequent case), it would |
| * require to rework tx_buf so each data would actualy fit 16 bits. |
| * So we'd rather write only one data at the time. Hence the transmit |
| * path works the same whether FIFOs are available (and enabled) or not. |
| */ |
| slave_config->direction = DMA_MEM_TO_DEV; |
| if (dmaengine_slave_config(master->dma_tx, slave_config)) { |
| dev_err(&as->pdev->dev, |
| "failed to configure tx dma channel\n"); |
| err = -EINVAL; |
| } |
| |
| /* |
| * This driver configures the spi controller for master mode (MSTR bit |
| * set to '1' in the Mode Register). |
| * So according to the datasheet, when FIFOs are available (and |
| * enabled), the Receive FIFO operates in Single Data Mode. |
| * So the receive path works the same whether FIFOs are available (and |
| * enabled) or not. |
| */ |
| slave_config->direction = DMA_DEV_TO_MEM; |
| if (dmaengine_slave_config(master->dma_rx, slave_config)) { |
| dev_err(&as->pdev->dev, |
| "failed to configure rx dma channel\n"); |
| err = -EINVAL; |
| } |
| |
| return err; |
| } |
| |
| static int atmel_spi_configure_dma(struct spi_master *master, |
| struct atmel_spi *as) |
| { |
| struct dma_slave_config slave_config; |
| struct device *dev = &as->pdev->dev; |
| int err; |
| |
| dma_cap_mask_t mask; |
| dma_cap_zero(mask); |
| dma_cap_set(DMA_SLAVE, mask); |
| |
| master->dma_tx = dma_request_slave_channel_reason(dev, "tx"); |
| if (IS_ERR(master->dma_tx)) { |
| err = PTR_ERR(master->dma_tx); |
| if (err == -EPROBE_DEFER) { |
| dev_warn(dev, "no DMA channel available at the moment\n"); |
| goto error_clear; |
| } |
| dev_err(dev, |
| "DMA TX channel not available, SPI unable to use DMA\n"); |
| err = -EBUSY; |
| goto error_clear; |
| } |
| |
| /* |
| * No reason to check EPROBE_DEFER here since we have already requested |
| * tx channel. If it fails here, it's for another reason. |
| */ |
| master->dma_rx = dma_request_slave_channel(dev, "rx"); |
| |
| if (!master->dma_rx) { |
| dev_err(dev, |
| "DMA RX channel not available, SPI unable to use DMA\n"); |
| err = -EBUSY; |
| goto error; |
| } |
| |
| err = atmel_spi_dma_slave_config(as, &slave_config, 8); |
| if (err) |
| goto error; |
| |
| dev_info(&as->pdev->dev, |
| "Using %s (tx) and %s (rx) for DMA transfers\n", |
| dma_chan_name(master->dma_tx), |
| dma_chan_name(master->dma_rx)); |
| |
| return 0; |
| error: |
| if (master->dma_rx) |
| dma_release_channel(master->dma_rx); |
| if (!IS_ERR(master->dma_tx)) |
| dma_release_channel(master->dma_tx); |
| error_clear: |
| master->dma_tx = master->dma_rx = NULL; |
| return err; |
| } |
| |
| static void atmel_spi_stop_dma(struct spi_master *master) |
| { |
| if (master->dma_rx) |
| dmaengine_terminate_all(master->dma_rx); |
| if (master->dma_tx) |
| dmaengine_terminate_all(master->dma_tx); |
| } |
| |
| static void atmel_spi_release_dma(struct spi_master *master) |
| { |
| if (master->dma_rx) { |
| dma_release_channel(master->dma_rx); |
| master->dma_rx = NULL; |
| } |
| if (master->dma_tx) { |
| dma_release_channel(master->dma_tx); |
| master->dma_tx = NULL; |
| } |
| } |
| |
| /* This function is called by the DMA driver from tasklet context */ |
| static void dma_callback(void *data) |
| { |
| struct spi_master *master = data; |
| struct atmel_spi *as = spi_master_get_devdata(master); |
| |
| if (is_vmalloc_addr(as->current_transfer->rx_buf) && |
| IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) { |
| memcpy(as->current_transfer->rx_buf, as->addr_rx_bbuf, |
| as->current_transfer->len); |
| } |
| complete(&as->xfer_completion); |
| } |
| |
| /* |
| * Next transfer using PIO without FIFO. |
| */ |
| static void atmel_spi_next_xfer_single(struct spi_master *master, |
| struct spi_transfer *xfer) |
| { |
| struct atmel_spi *as = spi_master_get_devdata(master); |
| unsigned long xfer_pos = xfer->len - as->current_remaining_bytes; |
| |
| dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_pio\n"); |
| |
| /* Make sure data is not remaining in RDR */ |
| spi_readl(as, RDR); |
| while (spi_readl(as, SR) & SPI_BIT(RDRF)) { |
| spi_readl(as, RDR); |
| cpu_relax(); |
| } |
| |
| if (xfer->bits_per_word > 8) |
| spi_writel(as, TDR, *(u16 *)(xfer->tx_buf + xfer_pos)); |
| else |
| spi_writel(as, TDR, *(u8 *)(xfer->tx_buf + xfer_pos)); |
| |
| dev_dbg(master->dev.parent, |
| " start pio xfer %p: len %u tx %p rx %p bitpw %d\n", |
| xfer, xfer->len, xfer->tx_buf, xfer->rx_buf, |
| xfer->bits_per_word); |
| |
| /* Enable relevant interrupts */ |
| spi_writel(as, IER, SPI_BIT(RDRF) | SPI_BIT(OVRES)); |
| } |
| |
| /* |
| * Next transfer using PIO with FIFO. |
| */ |
| static void atmel_spi_next_xfer_fifo(struct spi_master *master, |
| struct spi_transfer *xfer) |
| { |
| struct atmel_spi *as = spi_master_get_devdata(master); |
| u32 current_remaining_data, num_data; |
| u32 offset = xfer->len - as->current_remaining_bytes; |
| const u16 *words = (const u16 *)((u8 *)xfer->tx_buf + offset); |
| const u8 *bytes = (const u8 *)((u8 *)xfer->tx_buf + offset); |
| u16 td0, td1; |
| u32 fifomr; |
| |
| dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_fifo\n"); |
| |
| /* Compute the number of data to transfer in the current iteration */ |
| current_remaining_data = ((xfer->bits_per_word > 8) ? |
| ((u32)as->current_remaining_bytes >> 1) : |
| (u32)as->current_remaining_bytes); |
| num_data = min(current_remaining_data, as->fifo_size); |
| |
| /* Flush RX and TX FIFOs */ |
| spi_writel(as, CR, SPI_BIT(RXFCLR) | SPI_BIT(TXFCLR)); |
| while (spi_readl(as, FLR)) |
| cpu_relax(); |
| |
| /* Set RX FIFO Threshold to the number of data to transfer */ |
| fifomr = spi_readl(as, FMR); |
| spi_writel(as, FMR, SPI_BFINS(RXFTHRES, num_data, fifomr)); |
| |
| /* Clear FIFO flags in the Status Register, especially RXFTHF */ |
| (void)spi_readl(as, SR); |
| |
| /* Fill TX FIFO */ |
| while (num_data >= 2) { |
| if (xfer->bits_per_word > 8) { |
| td0 = *words++; |
| td1 = *words++; |
| } else { |
| td0 = *bytes++; |
| td1 = *bytes++; |
| } |
| |
| spi_writel(as, TDR, (td1 << 16) | td0); |
| num_data -= 2; |
| } |
| |
| if (num_data) { |
| if (xfer->bits_per_word > 8) |
| td0 = *words++; |
| else |
| td0 = *bytes++; |
| |
| spi_writew(as, TDR, td0); |
| num_data--; |
| } |
| |
| dev_dbg(master->dev.parent, |
| " start fifo xfer %p: len %u tx %p rx %p bitpw %d\n", |
| xfer, xfer->len, xfer->tx_buf, xfer->rx_buf, |
| xfer->bits_per_word); |
| |
| /* |
| * Enable RX FIFO Threshold Flag interrupt to be notified about |
| * transfer completion. |
| */ |
| spi_writel(as, IER, SPI_BIT(RXFTHF) | SPI_BIT(OVRES)); |
| } |
| |
| /* |
| * Next transfer using PIO. |
| */ |
| static void atmel_spi_next_xfer_pio(struct spi_master *master, |
| struct spi_transfer *xfer) |
| { |
| struct atmel_spi *as = spi_master_get_devdata(master); |
| |
| if (as->fifo_size) |
| atmel_spi_next_xfer_fifo(master, xfer); |
| else |
| atmel_spi_next_xfer_single(master, xfer); |
| } |
| |
| /* |
| * Submit next transfer for DMA. |
| */ |
| static int atmel_spi_next_xfer_dma_submit(struct spi_master *master, |
| struct spi_transfer *xfer, |
| u32 *plen) |
| { |
| struct atmel_spi *as = spi_master_get_devdata(master); |
| struct dma_chan *rxchan = master->dma_rx; |
| struct dma_chan *txchan = master->dma_tx; |
| struct dma_async_tx_descriptor *rxdesc; |
| struct dma_async_tx_descriptor *txdesc; |
| struct dma_slave_config slave_config; |
| dma_cookie_t cookie; |
| |
| dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_dma_submit\n"); |
| |
| /* Check that the channels are available */ |
| if (!rxchan || !txchan) |
| return -ENODEV; |
| |
| /* release lock for DMA operations */ |
| atmel_spi_unlock(as); |
| |
| *plen = xfer->len; |
| |
| if (atmel_spi_dma_slave_config(as, &slave_config, |
| xfer->bits_per_word)) |
| goto err_exit; |
| |
| /* Send both scatterlists */ |
| if (atmel_spi_is_vmalloc_xfer(xfer) && |
| IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) { |
| rxdesc = dmaengine_prep_slave_single(rxchan, |
| as->dma_addr_rx_bbuf, |
| xfer->len, |
| DMA_DEV_TO_MEM, |
| DMA_PREP_INTERRUPT | |
| DMA_CTRL_ACK); |
| } else { |
| rxdesc = dmaengine_prep_slave_sg(rxchan, |
| xfer->rx_sg.sgl, |
| xfer->rx_sg.nents, |
| DMA_DEV_TO_MEM, |
| DMA_PREP_INTERRUPT | |
| DMA_CTRL_ACK); |
| } |
| if (!rxdesc) |
| goto err_dma; |
| |
| if (atmel_spi_is_vmalloc_xfer(xfer) && |
| IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) { |
| memcpy(as->addr_tx_bbuf, xfer->tx_buf, xfer->len); |
| txdesc = dmaengine_prep_slave_single(txchan, |
| as->dma_addr_tx_bbuf, |
| xfer->len, DMA_MEM_TO_DEV, |
| DMA_PREP_INTERRUPT | |
| DMA_CTRL_ACK); |
| } else { |
| txdesc = dmaengine_prep_slave_sg(txchan, |
| xfer->tx_sg.sgl, |
| xfer->tx_sg.nents, |
| DMA_MEM_TO_DEV, |
| DMA_PREP_INTERRUPT | |
| DMA_CTRL_ACK); |
| } |
| if (!txdesc) |
| goto err_dma; |
| |
| dev_dbg(master->dev.parent, |
| " start dma xfer %p: len %u tx %p/%08llx rx %p/%08llx\n", |
| xfer, xfer->len, xfer->tx_buf, (unsigned long long)xfer->tx_dma, |
| xfer->rx_buf, (unsigned long long)xfer->rx_dma); |
| |
| /* Enable relevant interrupts */ |
| spi_writel(as, IER, SPI_BIT(OVRES)); |
| |
| /* Put the callback on the RX transfer only, that should finish last */ |
| rxdesc->callback = dma_callback; |
| rxdesc->callback_param = master; |
| |
| /* Submit and fire RX and TX with TX last so we're ready to read! */ |
| cookie = rxdesc->tx_submit(rxdesc); |
| if (dma_submit_error(cookie)) |
| goto err_dma; |
| cookie = txdesc->tx_submit(txdesc); |
| if (dma_submit_error(cookie)) |
| goto err_dma; |
| rxchan->device->device_issue_pending(rxchan); |
| txchan->device->device_issue_pending(txchan); |
| |
| /* take back lock */ |
| atmel_spi_lock(as); |
| return 0; |
| |
| err_dma: |
| spi_writel(as, IDR, SPI_BIT(OVRES)); |
| atmel_spi_stop_dma(master); |
| err_exit: |
| atmel_spi_lock(as); |
| return -ENOMEM; |
| } |
| |
| static void atmel_spi_next_xfer_data(struct spi_master *master, |
| struct spi_transfer *xfer, |
| dma_addr_t *tx_dma, |
| dma_addr_t *rx_dma, |
| u32 *plen) |
| { |
| *rx_dma = xfer->rx_dma + xfer->len - *plen; |
| *tx_dma = xfer->tx_dma + xfer->len - *plen; |
| if (*plen > master->max_dma_len) |
| *plen = master->max_dma_len; |
| } |
| |
| static int atmel_spi_set_xfer_speed(struct atmel_spi *as, |
| struct spi_device *spi, |
| struct spi_transfer *xfer) |
| { |
| u32 scbr, csr; |
| unsigned long bus_hz; |
| |
| /* v1 chips start out at half the peripheral bus speed. */ |
| bus_hz = as->spi_clk; |
| if (!atmel_spi_is_v2(as)) |
| bus_hz /= 2; |
| |
| /* |
| * Calculate the lowest divider that satisfies the |
| * constraint, assuming div32/fdiv/mbz == 0. |
| */ |
| scbr = DIV_ROUND_UP(bus_hz, xfer->speed_hz); |
| |
| /* |
| * If the resulting divider doesn't fit into the |
| * register bitfield, we can't satisfy the constraint. |
| */ |
| if (scbr >= (1 << SPI_SCBR_SIZE)) { |
| dev_err(&spi->dev, |
| "setup: %d Hz too slow, scbr %u; min %ld Hz\n", |
| xfer->speed_hz, scbr, bus_hz/255); |
| return -EINVAL; |
| } |
| if (scbr == 0) { |
| dev_err(&spi->dev, |
| "setup: %d Hz too high, scbr %u; max %ld Hz\n", |
| xfer->speed_hz, scbr, bus_hz); |
| return -EINVAL; |
| } |
| csr = spi_readl(as, CSR0 + 4 * spi->chip_select); |
| csr = SPI_BFINS(SCBR, scbr, csr); |
| spi_writel(as, CSR0 + 4 * spi->chip_select, csr); |
| |
| return 0; |
| } |
| |
| /* |
| * Submit next transfer for PDC. |
| * lock is held, spi irq is blocked |
| */ |
| static void atmel_spi_pdc_next_xfer(struct spi_master *master, |
| struct spi_message *msg, |
| struct spi_transfer *xfer) |
| { |
| struct atmel_spi *as = spi_master_get_devdata(master); |
| u32 len; |
| dma_addr_t tx_dma, rx_dma; |
| |
| spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); |
| |
| len = as->current_remaining_bytes; |
| atmel_spi_next_xfer_data(master, xfer, &tx_dma, &rx_dma, &len); |
| as->current_remaining_bytes -= len; |
| |
| spi_writel(as, RPR, rx_dma); |
| spi_writel(as, TPR, tx_dma); |
| |
| if (msg->spi->bits_per_word > 8) |
| len >>= 1; |
| spi_writel(as, RCR, len); |
| spi_writel(as, TCR, len); |
| |
| dev_dbg(&msg->spi->dev, |
| " start xfer %p: len %u tx %p/%08llx rx %p/%08llx\n", |
| xfer, xfer->len, xfer->tx_buf, |
| (unsigned long long)xfer->tx_dma, xfer->rx_buf, |
| (unsigned long long)xfer->rx_dma); |
| |
| if (as->current_remaining_bytes) { |
| len = as->current_remaining_bytes; |
| atmel_spi_next_xfer_data(master, xfer, &tx_dma, &rx_dma, &len); |
| as->current_remaining_bytes -= len; |
| |
| spi_writel(as, RNPR, rx_dma); |
| spi_writel(as, TNPR, tx_dma); |
| |
| if (msg->spi->bits_per_word > 8) |
| len >>= 1; |
| spi_writel(as, RNCR, len); |
| spi_writel(as, TNCR, len); |
| |
| dev_dbg(&msg->spi->dev, |
| " next xfer %p: len %u tx %p/%08llx rx %p/%08llx\n", |
| xfer, xfer->len, xfer->tx_buf, |
| (unsigned long long)xfer->tx_dma, xfer->rx_buf, |
| (unsigned long long)xfer->rx_dma); |
| } |
| |
| /* REVISIT: We're waiting for RXBUFF before we start the next |
| * transfer because we need to handle some difficult timing |
| * issues otherwise. If we wait for TXBUFE in one transfer and |
| * then starts waiting for RXBUFF in the next, it's difficult |
| * to tell the difference between the RXBUFF interrupt we're |
| * actually waiting for and the RXBUFF interrupt of the |
| * previous transfer. |
| * |
| * It should be doable, though. Just not now... |
| */ |
| spi_writel(as, IER, SPI_BIT(RXBUFF) | SPI_BIT(OVRES)); |
| spi_writel(as, PTCR, SPI_BIT(TXTEN) | SPI_BIT(RXTEN)); |
| } |
| |
| /* |
| * For DMA, tx_buf/tx_dma have the same relationship as rx_buf/rx_dma: |
| * - The buffer is either valid for CPU access, else NULL |
| * - If the buffer is valid, so is its DMA address |
| * |
| * This driver manages the dma address unless message->is_dma_mapped. |
| */ |
| static int |
| atmel_spi_dma_map_xfer(struct atmel_spi *as, struct spi_transfer *xfer) |
| { |
| struct device *dev = &as->pdev->dev; |
| |
| xfer->tx_dma = xfer->rx_dma = INVALID_DMA_ADDRESS; |
| if (xfer->tx_buf) { |
| /* tx_buf is a const void* where we need a void * for the dma |
| * mapping */ |
| void *nonconst_tx = (void *)xfer->tx_buf; |
| |
| xfer->tx_dma = dma_map_single(dev, |
| nonconst_tx, xfer->len, |
| DMA_TO_DEVICE); |
| if (dma_mapping_error(dev, xfer->tx_dma)) |
| return -ENOMEM; |
| } |
| if (xfer->rx_buf) { |
| xfer->rx_dma = dma_map_single(dev, |
| xfer->rx_buf, xfer->len, |
| DMA_FROM_DEVICE); |
| if (dma_mapping_error(dev, xfer->rx_dma)) { |
| if (xfer->tx_buf) |
| dma_unmap_single(dev, |
| xfer->tx_dma, xfer->len, |
| DMA_TO_DEVICE); |
| return -ENOMEM; |
| } |
| } |
| return 0; |
| } |
| |
| static void atmel_spi_dma_unmap_xfer(struct spi_master *master, |
| struct spi_transfer *xfer) |
| { |
| if (xfer->tx_dma != INVALID_DMA_ADDRESS) |
| dma_unmap_single(master->dev.parent, xfer->tx_dma, |
| xfer->len, DMA_TO_DEVICE); |
| if (xfer->rx_dma != INVALID_DMA_ADDRESS) |
| dma_unmap_single(master->dev.parent, xfer->rx_dma, |
| xfer->len, DMA_FROM_DEVICE); |
| } |
| |
| static void atmel_spi_disable_pdc_transfer(struct atmel_spi *as) |
| { |
| spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); |
| } |
| |
| static void |
| atmel_spi_pump_single_data(struct atmel_spi *as, struct spi_transfer *xfer) |
| { |
| u8 *rxp; |
| u16 *rxp16; |
| unsigned long xfer_pos = xfer->len - as->current_remaining_bytes; |
| |
| if (xfer->bits_per_word > 8) { |
| rxp16 = (u16 *)(((u8 *)xfer->rx_buf) + xfer_pos); |
| *rxp16 = spi_readl(as, RDR); |
| } else { |
| rxp = ((u8 *)xfer->rx_buf) + xfer_pos; |
| *rxp = spi_readl(as, RDR); |
| } |
| if (xfer->bits_per_word > 8) { |
| if (as->current_remaining_bytes > 2) |
| as->current_remaining_bytes -= 2; |
| else |
| as->current_remaining_bytes = 0; |
| } else { |
| as->current_remaining_bytes--; |
| } |
| } |
| |
| static void |
| atmel_spi_pump_fifo_data(struct atmel_spi *as, struct spi_transfer *xfer) |
| { |
| u32 fifolr = spi_readl(as, FLR); |
| u32 num_bytes, num_data = SPI_BFEXT(RXFL, fifolr); |
| u32 offset = xfer->len - as->current_remaining_bytes; |
| u16 *words = (u16 *)((u8 *)xfer->rx_buf + offset); |
| u8 *bytes = (u8 *)((u8 *)xfer->rx_buf + offset); |
| u16 rd; /* RD field is the lowest 16 bits of RDR */ |
| |
| /* Update the number of remaining bytes to transfer */ |
| num_bytes = ((xfer->bits_per_word > 8) ? |
| (num_data << 1) : |
| num_data); |
| |
| if (as->current_remaining_bytes > num_bytes) |
| as->current_remaining_bytes -= num_bytes; |
| else |
| as->current_remaining_bytes = 0; |
| |
| /* Handle odd number of bytes when data are more than 8bit width */ |
| if (xfer->bits_per_word > 8) |
| as->current_remaining_bytes &= ~0x1; |
| |
| /* Read data */ |
| while (num_data) { |
| rd = spi_readl(as, RDR); |
| if (xfer->bits_per_word > 8) |
| *words++ = rd; |
| else |
| *bytes++ = rd; |
| num_data--; |
| } |
| } |
| |
| /* Called from IRQ |
| * |
| * Must update "current_remaining_bytes" to keep track of data |
| * to transfer. |
| */ |
| static void |
| atmel_spi_pump_pio_data(struct atmel_spi *as, struct spi_transfer *xfer) |
| { |
| if (as->fifo_size) |
| atmel_spi_pump_fifo_data(as, xfer); |
| else |
| atmel_spi_pump_single_data(as, xfer); |
| } |
| |
| /* Interrupt |
| * |
| * No need for locking in this Interrupt handler: done_status is the |
| * only information modified. |
| */ |
| static irqreturn_t |
| atmel_spi_pio_interrupt(int irq, void *dev_id) |
| { |
| struct spi_master *master = dev_id; |
| struct atmel_spi *as = spi_master_get_devdata(master); |
| u32 status, pending, imr; |
| struct spi_transfer *xfer; |
| int ret = IRQ_NONE; |
| |
| imr = spi_readl(as, IMR); |
| status = spi_readl(as, SR); |
| pending = status & imr; |
| |
| if (pending & SPI_BIT(OVRES)) { |
| ret = IRQ_HANDLED; |
| spi_writel(as, IDR, SPI_BIT(OVRES)); |
| dev_warn(master->dev.parent, "overrun\n"); |
| |
| /* |
| * When we get an overrun, we disregard the current |
| * transfer. Data will not be copied back from any |
| * bounce buffer and msg->actual_len will not be |
| * updated with the last xfer. |
| * |
| * We will also not process any remaning transfers in |
| * the message. |
| */ |
| as->done_status = -EIO; |
| smp_wmb(); |
| |
| /* Clear any overrun happening while cleaning up */ |
| spi_readl(as, SR); |
| |
| complete(&as->xfer_completion); |
| |
| } else if (pending & (SPI_BIT(RDRF) | SPI_BIT(RXFTHF))) { |
| atmel_spi_lock(as); |
| |
| if (as->current_remaining_bytes) { |
| ret = IRQ_HANDLED; |
| xfer = as->current_transfer; |
| atmel_spi_pump_pio_data(as, xfer); |
| if (!as->current_remaining_bytes) |
| spi_writel(as, IDR, pending); |
| |
| complete(&as->xfer_completion); |
| } |
| |
| atmel_spi_unlock(as); |
| } else { |
| WARN_ONCE(pending, "IRQ not handled, pending = %x\n", pending); |
| ret = IRQ_HANDLED; |
| spi_writel(as, IDR, pending); |
| } |
| |
| return ret; |
| } |
| |
| static irqreturn_t |
| atmel_spi_pdc_interrupt(int irq, void *dev_id) |
| { |
| struct spi_master *master = dev_id; |
| struct atmel_spi *as = spi_master_get_devdata(master); |
| u32 status, pending, imr; |
| int ret = IRQ_NONE; |
| |
| imr = spi_readl(as, IMR); |
| status = spi_readl(as, SR); |
| pending = status & imr; |
| |
| if (pending & SPI_BIT(OVRES)) { |
| |
| ret = IRQ_HANDLED; |
| |
| spi_writel(as, IDR, (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX) |
| | SPI_BIT(OVRES))); |
| |
| /* Clear any overrun happening while cleaning up */ |
| spi_readl(as, SR); |
| |
| as->done_status = -EIO; |
| |
| complete(&as->xfer_completion); |
| |
| } else if (pending & (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX))) { |
| ret = IRQ_HANDLED; |
| |
| spi_writel(as, IDR, pending); |
| |
| complete(&as->xfer_completion); |
| } |
| |
| return ret; |
| } |
| |
| static int atmel_spi_setup(struct spi_device *spi) |
| { |
| struct atmel_spi *as; |
| struct atmel_spi_device *asd; |
| u32 csr; |
| unsigned int bits = spi->bits_per_word; |
| |
| as = spi_master_get_devdata(spi->master); |
| |
| /* see notes above re chipselect */ |
| if (!atmel_spi_is_v2(as) |
| && spi->chip_select == 0 |
| && (spi->mode & SPI_CS_HIGH)) { |
| dev_dbg(&spi->dev, "setup: can't be active-high\n"); |
| return -EINVAL; |
| } |
| |
| csr = SPI_BF(BITS, bits - 8); |
| if (spi->mode & SPI_CPOL) |
| csr |= SPI_BIT(CPOL); |
| if (!(spi->mode & SPI_CPHA)) |
| csr |= SPI_BIT(NCPHA); |
| if (!as->use_cs_gpios) |
| csr |= SPI_BIT(CSAAT); |
| |
| /* DLYBS is mostly irrelevant since we manage chipselect using GPIOs. |
| */ |
| csr |= SPI_BF(DLYBS, 0); |
| |
| /* DLYBCT adds delays between words. This is useful for slow devices |
| * that need a bit of time to setup the next transfer. |
| */ |
| csr |= SPI_BF(DLYBCT, |
| (as->spi_clk / 1000000 * spi->word_delay_usecs) >> 5); |
| |
| asd = spi->controller_state; |
| if (!asd) { |
| asd = kzalloc(sizeof(struct atmel_spi_device), GFP_KERNEL); |
| if (!asd) |
| return -ENOMEM; |
| |
| /* |
| * If use_cs_gpios is true this means that we have "cs-gpios" |
| * defined in the device tree node so we should have |
| * gotten the GPIO lines from the device tree inside the |
| * SPI core. Warn if this is not the case but continue since |
| * CS GPIOs are after all optional. |
| */ |
| if (as->use_cs_gpios) { |
| if (!spi->cs_gpiod) { |
| dev_err(&spi->dev, |
| "host claims to use CS GPIOs but no CS found in DT by the SPI core\n"); |
| } |
| asd->npcs_pin = spi->cs_gpiod; |
| } |
| |
| spi->controller_state = asd; |
| } |
| |
| asd->csr = csr; |
| |
| dev_dbg(&spi->dev, |
| "setup: bpw %u mode 0x%x -> csr%d %08x\n", |
| bits, spi->mode, spi->chip_select, csr); |
| |
| if (!atmel_spi_is_v2(as)) |
| spi_writel(as, CSR0 + 4 * spi->chip_select, csr); |
| |
| return 0; |
| } |
| |
| static int atmel_spi_one_transfer(struct spi_master *master, |
| struct spi_message *msg, |
| struct spi_transfer *xfer) |
| { |
| struct atmel_spi *as; |
| struct spi_device *spi = msg->spi; |
| u8 bits; |
| u32 len; |
| struct atmel_spi_device *asd; |
| int timeout; |
| int ret; |
| unsigned long dma_timeout; |
| |
| as = spi_master_get_devdata(master); |
| |
| if (!(xfer->tx_buf || xfer->rx_buf) && xfer->len) { |
| dev_dbg(&spi->dev, "missing rx or tx buf\n"); |
| return -EINVAL; |
| } |
| |
| asd = spi->controller_state; |
| bits = (asd->csr >> 4) & 0xf; |
| if (bits != xfer->bits_per_word - 8) { |
| dev_dbg(&spi->dev, |
| "you can't yet change bits_per_word in transfers\n"); |
| return -ENOPROTOOPT; |
| } |
| |
| /* |
| * DMA map early, for performance (empties dcache ASAP) and |
| * better fault reporting. |
| */ |
| if ((!msg->is_dma_mapped) |
| && as->use_pdc) { |
| if (atmel_spi_dma_map_xfer(as, xfer) < 0) |
| return -ENOMEM; |
| } |
| |
| atmel_spi_set_xfer_speed(as, msg->spi, xfer); |
| |
| as->done_status = 0; |
| as->current_transfer = xfer; |
| as->current_remaining_bytes = xfer->len; |
| while (as->current_remaining_bytes) { |
| reinit_completion(&as->xfer_completion); |
| |
| if (as->use_pdc) { |
| atmel_spi_pdc_next_xfer(master, msg, xfer); |
| } else if (atmel_spi_use_dma(as, xfer)) { |
| len = as->current_remaining_bytes; |
| ret = atmel_spi_next_xfer_dma_submit(master, |
| xfer, &len); |
| if (ret) { |
| dev_err(&spi->dev, |
| "unable to use DMA, fallback to PIO\n"); |
| atmel_spi_next_xfer_pio(master, xfer); |
| } else { |
| as->current_remaining_bytes -= len; |
| if (as->current_remaining_bytes < 0) |
| as->current_remaining_bytes = 0; |
| } |
| } else { |
| atmel_spi_next_xfer_pio(master, xfer); |
| } |
| |
| /* interrupts are disabled, so free the lock for schedule */ |
| atmel_spi_unlock(as); |
| dma_timeout = wait_for_completion_timeout(&as->xfer_completion, |
| SPI_DMA_TIMEOUT); |
| atmel_spi_lock(as); |
| if (WARN_ON(dma_timeout == 0)) { |
| dev_err(&spi->dev, "spi transfer timeout\n"); |
| as->done_status = -EIO; |
| } |
| |
| if (as->done_status) |
| break; |
| } |
| |
| if (as->done_status) { |
| if (as->use_pdc) { |
| dev_warn(master->dev.parent, |
| "overrun (%u/%u remaining)\n", |
| spi_readl(as, TCR), spi_readl(as, RCR)); |
| |
| /* |
| * Clean up DMA registers and make sure the data |
| * registers are empty. |
| */ |
| spi_writel(as, RNCR, 0); |
| spi_writel(as, TNCR, 0); |
| spi_writel(as, RCR, 0); |
| spi_writel(as, TCR, 0); |
| for (timeout = 1000; timeout; timeout--) |
| if (spi_readl(as, SR) & SPI_BIT(TXEMPTY)) |
| break; |
| if (!timeout) |
| dev_warn(master->dev.parent, |
| "timeout waiting for TXEMPTY"); |
| while (spi_readl(as, SR) & SPI_BIT(RDRF)) |
| spi_readl(as, RDR); |
| |
| /* Clear any overrun happening while cleaning up */ |
| spi_readl(as, SR); |
| |
| } else if (atmel_spi_use_dma(as, xfer)) { |
| atmel_spi_stop_dma(master); |
| } |
| |
| if (!msg->is_dma_mapped |
| && as->use_pdc) |
| atmel_spi_dma_unmap_xfer(master, xfer); |
| |
| return 0; |
| |
| } else { |
| /* only update length if no error */ |
| msg->actual_length += xfer->len; |
| } |
| |
| if (!msg->is_dma_mapped |
| && as->use_pdc) |
| atmel_spi_dma_unmap_xfer(master, xfer); |
| |
| if (xfer->delay_usecs) |
| udelay(xfer->delay_usecs); |
| |
| if (xfer->cs_change) { |
| if (list_is_last(&xfer->transfer_list, |
| &msg->transfers)) { |
| as->keep_cs = true; |
| } else { |
| as->cs_active = !as->cs_active; |
| if (as->cs_active) |
| cs_activate(as, msg->spi); |
| else |
| cs_deactivate(as, msg->spi); |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int atmel_spi_transfer_one_message(struct spi_master *master, |
| struct spi_message *msg) |
| { |
| struct atmel_spi *as; |
| struct spi_transfer *xfer; |
| struct spi_device *spi = msg->spi; |
| int ret = 0; |
| |
| as = spi_master_get_devdata(master); |
| |
| dev_dbg(&spi->dev, "new message %p submitted for %s\n", |
| msg, dev_name(&spi->dev)); |
| |
| atmel_spi_lock(as); |
| cs_activate(as, spi); |
| |
| as->cs_active = true; |
| as->keep_cs = false; |
| |
| msg->status = 0; |
| msg->actual_length = 0; |
| |
| list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
| ret = atmel_spi_one_transfer(master, msg, xfer); |
| if (ret) |
| goto msg_done; |
| } |
| |
| if (as->use_pdc) |
| atmel_spi_disable_pdc_transfer(as); |
| |
| list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
| dev_dbg(&spi->dev, |
| " xfer %p: len %u tx %p/%pad rx %p/%pad\n", |
| xfer, xfer->len, |
| xfer->tx_buf, &xfer->tx_dma, |
| xfer->rx_buf, &xfer->rx_dma); |
| } |
| |
| msg_done: |
| if (!as->keep_cs) |
| cs_deactivate(as, msg->spi); |
| |
| atmel_spi_unlock(as); |
| |
| msg->status = as->done_status; |
| spi_finalize_current_message(spi->master); |
| |
| return ret; |
| } |
| |
| static void atmel_spi_cleanup(struct spi_device *spi) |
| { |
| struct atmel_spi_device *asd = spi->controller_state; |
| |
| if (!asd) |
| return; |
| |
| spi->controller_state = NULL; |
| kfree(asd); |
| } |
| |
| static inline unsigned int atmel_get_version(struct atmel_spi *as) |
| { |
| return spi_readl(as, VERSION) & 0x00000fff; |
| } |
| |
| static void atmel_get_caps(struct atmel_spi *as) |
| { |
| unsigned int version; |
| |
| version = atmel_get_version(as); |
| |
| as->caps.is_spi2 = version > 0x121; |
| as->caps.has_wdrbt = version >= 0x210; |
| as->caps.has_dma_support = version >= 0x212; |
| as->caps.has_pdc_support = version < 0x212; |
| } |
| |
| static void atmel_spi_init(struct atmel_spi *as) |
| { |
| spi_writel(as, CR, SPI_BIT(SWRST)); |
| spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */ |
| |
| /* It is recommended to enable FIFOs first thing after reset */ |
| if (as->fifo_size) |
| spi_writel(as, CR, SPI_BIT(FIFOEN)); |
| |
| if (as->caps.has_wdrbt) { |
| spi_writel(as, MR, SPI_BIT(WDRBT) | SPI_BIT(MODFDIS) |
| | SPI_BIT(MSTR)); |
| } else { |
| spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS)); |
| } |
| |
| if (as->use_pdc) |
| spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); |
| spi_writel(as, CR, SPI_BIT(SPIEN)); |
| } |
| |
| static int atmel_spi_probe(struct platform_device *pdev) |
| { |
| struct resource *regs; |
| int irq; |
| struct clk *clk; |
| int ret; |
| struct spi_master *master; |
| struct atmel_spi *as; |
| |
| /* Select default pin state */ |
| pinctrl_pm_select_default_state(&pdev->dev); |
| |
| regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| if (!regs) |
| return -ENXIO; |
| |
| irq = platform_get_irq(pdev, 0); |
| if (irq < 0) |
| return irq; |
| |
| clk = devm_clk_get(&pdev->dev, "spi_clk"); |
| if (IS_ERR(clk)) |
| return PTR_ERR(clk); |
| |
| /* setup spi core then atmel-specific driver state */ |
| ret = -ENOMEM; |
| master = spi_alloc_master(&pdev->dev, sizeof(*as)); |
| if (!master) |
| goto out_free; |
| |
| /* the spi->mode bits understood by this driver: */ |
| master->use_gpio_descriptors = true; |
| master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; |
| master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 16); |
| master->dev.of_node = pdev->dev.of_node; |
| master->bus_num = pdev->id; |
| master->num_chipselect = master->dev.of_node ? 0 : 4; |
| master->setup = atmel_spi_setup; |
| master->flags = (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX); |
| master->transfer_one_message = atmel_spi_transfer_one_message; |
| master->cleanup = atmel_spi_cleanup; |
| master->auto_runtime_pm = true; |
| master->max_dma_len = SPI_MAX_DMA_XFER; |
| master->can_dma = atmel_spi_can_dma; |
| platform_set_drvdata(pdev, master); |
| |
| as = spi_master_get_devdata(master); |
| |
| spin_lock_init(&as->lock); |
| |
| as->pdev = pdev; |
| as->regs = devm_ioremap_resource(&pdev->dev, regs); |
| if (IS_ERR(as->regs)) { |
| ret = PTR_ERR(as->regs); |
| goto out_unmap_regs; |
| } |
| as->phybase = regs->start; |
| as->irq = irq; |
| as->clk = clk; |
| |
| init_completion(&as->xfer_completion); |
| |
| atmel_get_caps(as); |
| |
| /* |
| * If there are chip selects in the device tree, those will be |
| * discovered by the SPI core when registering the SPI master |
| * and assigned to each SPI device. |
| */ |
| as->use_cs_gpios = true; |
| if (atmel_spi_is_v2(as) && |
| pdev->dev.of_node && |
| !of_get_property(pdev->dev.of_node, "cs-gpios", NULL)) { |
| as->use_cs_gpios = false; |
| master->num_chipselect = 4; |
| } |
| |
| as->use_dma = false; |
| as->use_pdc = false; |
| if (as->caps.has_dma_support) { |
| ret = atmel_spi_configure_dma(master, as); |
| if (ret == 0) { |
| as->use_dma = true; |
| } else if (ret == -EPROBE_DEFER) { |
| return ret; |
| } |
| } else if (as->caps.has_pdc_support) { |
| as->use_pdc = true; |
| } |
| |
| if (IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) { |
| as->addr_rx_bbuf = dma_alloc_coherent(&pdev->dev, |
| SPI_MAX_DMA_XFER, |
| &as->dma_addr_rx_bbuf, |
| GFP_KERNEL | GFP_DMA); |
| if (!as->addr_rx_bbuf) { |
| as->use_dma = false; |
| } else { |
| as->addr_tx_bbuf = dma_alloc_coherent(&pdev->dev, |
| SPI_MAX_DMA_XFER, |
| &as->dma_addr_tx_bbuf, |
| GFP_KERNEL | GFP_DMA); |
| if (!as->addr_tx_bbuf) { |
| as->use_dma = false; |
| dma_free_coherent(&pdev->dev, SPI_MAX_DMA_XFER, |
| as->addr_rx_bbuf, |
| as->dma_addr_rx_bbuf); |
| } |
| } |
| if (!as->use_dma) |
| dev_info(master->dev.parent, |
| " can not allocate dma coherent memory\n"); |
| } |
| |
| if (as->caps.has_dma_support && !as->use_dma) |
| dev_info(&pdev->dev, "Atmel SPI Controller using PIO only\n"); |
| |
| if (as->use_pdc) { |
| ret = devm_request_irq(&pdev->dev, irq, atmel_spi_pdc_interrupt, |
| 0, dev_name(&pdev->dev), master); |
| } else { |
| ret = devm_request_irq(&pdev->dev, irq, atmel_spi_pio_interrupt, |
| 0, dev_name(&pdev->dev), master); |
| } |
| if (ret) |
| goto out_unmap_regs; |
| |
| /* Initialize the hardware */ |
| ret = clk_prepare_enable(clk); |
| if (ret) |
| goto out_free_irq; |
| |
| as->spi_clk = clk_get_rate(clk); |
| |
| as->fifo_size = 0; |
| if (!of_property_read_u32(pdev->dev.of_node, "atmel,fifo-size", |
| &as->fifo_size)) { |
| dev_info(&pdev->dev, "Using FIFO (%u data)\n", as->fifo_size); |
| } |
| |
| atmel_spi_init(as); |
| |
| pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT); |
| pm_runtime_use_autosuspend(&pdev->dev); |
| pm_runtime_set_active(&pdev->dev); |
| pm_runtime_enable(&pdev->dev); |
| |
| ret = devm_spi_register_master(&pdev->dev, master); |
| if (ret) |
| goto out_free_dma; |
| |
| /* go! */ |
| dev_info(&pdev->dev, "Atmel SPI Controller version 0x%x at 0x%08lx (irq %d)\n", |
| atmel_get_version(as), (unsigned long)regs->start, |
| irq); |
| |
| return 0; |
| |
| out_free_dma: |
| pm_runtime_disable(&pdev->dev); |
| pm_runtime_set_suspended(&pdev->dev); |
| |
| if (as->use_dma) |
| atmel_spi_release_dma(master); |
| |
| spi_writel(as, CR, SPI_BIT(SWRST)); |
| spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */ |
| clk_disable_unprepare(clk); |
| out_free_irq: |
| out_unmap_regs: |
| out_free: |
| spi_master_put(master); |
| return ret; |
| } |
| |
| static int atmel_spi_remove(struct platform_device *pdev) |
| { |
| struct spi_master *master = platform_get_drvdata(pdev); |
| struct atmel_spi *as = spi_master_get_devdata(master); |
| |
| pm_runtime_get_sync(&pdev->dev); |
| |
| /* reset the hardware and block queue progress */ |
| if (as->use_dma) { |
| atmel_spi_stop_dma(master); |
| atmel_spi_release_dma(master); |
| if (IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) { |
| dma_free_coherent(&pdev->dev, SPI_MAX_DMA_XFER, |
| as->addr_tx_bbuf, |
| as->dma_addr_tx_bbuf); |
| dma_free_coherent(&pdev->dev, SPI_MAX_DMA_XFER, |
| as->addr_rx_bbuf, |
| as->dma_addr_rx_bbuf); |
| } |
| } |
| |
| spin_lock_irq(&as->lock); |
| spi_writel(as, CR, SPI_BIT(SWRST)); |
| spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */ |
| spi_readl(as, SR); |
| spin_unlock_irq(&as->lock); |
| |
| clk_disable_unprepare(as->clk); |
| |
| pm_runtime_put_noidle(&pdev->dev); |
| pm_runtime_disable(&pdev->dev); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_PM |
| static int atmel_spi_runtime_suspend(struct device *dev) |
| { |
| struct spi_master *master = dev_get_drvdata(dev); |
| struct atmel_spi *as = spi_master_get_devdata(master); |
| |
| clk_disable_unprepare(as->clk); |
| pinctrl_pm_select_sleep_state(dev); |
| |
| return 0; |
| } |
| |
| static int atmel_spi_runtime_resume(struct device *dev) |
| { |
| struct spi_master *master = dev_get_drvdata(dev); |
| struct atmel_spi *as = spi_master_get_devdata(master); |
| |
| pinctrl_pm_select_default_state(dev); |
| |
| return clk_prepare_enable(as->clk); |
| } |
| |
| #ifdef CONFIG_PM_SLEEP |
| static int atmel_spi_suspend(struct device *dev) |
| { |
| struct spi_master *master = dev_get_drvdata(dev); |
| int ret; |
| |
| /* Stop the queue running */ |
| ret = spi_master_suspend(master); |
| if (ret) |
| return ret; |
| |
| if (!pm_runtime_suspended(dev)) |
| atmel_spi_runtime_suspend(dev); |
| |
| return 0; |
| } |
| |
| static int atmel_spi_resume(struct device *dev) |
| { |
| struct spi_master *master = dev_get_drvdata(dev); |
| struct atmel_spi *as = spi_master_get_devdata(master); |
| int ret; |
| |
| ret = clk_prepare_enable(as->clk); |
| if (ret) |
| return ret; |
| |
| atmel_spi_init(as); |
| |
| clk_disable_unprepare(as->clk); |
| |
| if (!pm_runtime_suspended(dev)) { |
| ret = atmel_spi_runtime_resume(dev); |
| if (ret) |
| return ret; |
| } |
| |
| /* Start the queue running */ |
| return spi_master_resume(master); |
| } |
| #endif |
| |
| static const struct dev_pm_ops atmel_spi_pm_ops = { |
| SET_SYSTEM_SLEEP_PM_OPS(atmel_spi_suspend, atmel_spi_resume) |
| SET_RUNTIME_PM_OPS(atmel_spi_runtime_suspend, |
| atmel_spi_runtime_resume, NULL) |
| }; |
| #define ATMEL_SPI_PM_OPS (&atmel_spi_pm_ops) |
| #else |
| #define ATMEL_SPI_PM_OPS NULL |
| #endif |
| |
| #if defined(CONFIG_OF) |
| static const struct of_device_id atmel_spi_dt_ids[] = { |
| { .compatible = "atmel,at91rm9200-spi" }, |
| { /* sentinel */ } |
| }; |
| |
| MODULE_DEVICE_TABLE(of, atmel_spi_dt_ids); |
| #endif |
| |
| static struct platform_driver atmel_spi_driver = { |
| .driver = { |
| .name = "atmel_spi", |
| .pm = ATMEL_SPI_PM_OPS, |
| .of_match_table = of_match_ptr(atmel_spi_dt_ids), |
| }, |
| .probe = atmel_spi_probe, |
| .remove = atmel_spi_remove, |
| }; |
| module_platform_driver(atmel_spi_driver); |
| |
| MODULE_DESCRIPTION("Atmel AT32/AT91 SPI Controller driver"); |
| MODULE_AUTHOR("Haavard Skinnemoen (Atmel)"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS("platform:atmel_spi"); |